Condition responsive sense system and method

A condition responsive sense element system comprising

• a plurality of condition responsive sense elements providing a voltage output dependent on the condition, the condition being sensed being one of pressure, acceleration force and torque, the sense elements each having a bridge network with a bridge voltage node, a ground node, a plus output node and a minus output node,
• a voltage source,
• each bridge voltage node connected to the voltage source,
• an electronic circuit having first, second and third multiplexers, each having an output and a plurality of address input positions, the plus node of each sense element connected to a respective multiplexer address position of the first multiplexer, the minus node of each sense element connected to a respective multiplexer address position of the second multiplexer and the ground node of each sense element connected to a respective address position of the third multiplexer, a respective register connected to each multiplexer,
• a signal ground, the output of the third multiplexer connected to a signal ground,
• a signal conditioning circuit path, the signal conditioning circuit path comprising a differential amplifier having a plus and a minus input and an output, the output of the first multiplexer connected to the plus input of the differential amplifier, the output of the second multiplexer connected to the minus input of the differential amplifier, an offset correction network having a summing circuit with an output and inputs, the input connected to the output of the differential amplifier and an offset circuit controlled by a register to provide a correction proportional to bridge voltage, and a gain correction network having a variable gain amplifier having an input connected to the output of the offset correction network and controlled by a gain correction register,
• a digital port,
• an analog to digital converter having an input and an output, the output of the gain correction network inputted to the analog to digital converter to provide a digital signal corresponding to the sensed condition to the digital port,
• a logic control and a nonvolatile memory section, the nonvolatile memory section being connected to the several registers under the control of the logic control, the digital port forming an interface for transmitting data to and receiving data from an external controller, the nonvolatile memory providing data to the external controller enabling the external controller to perform mathematical error correction for the condition sensor signals and the logic control providing commands for obtaining sense element data from a selected sense element.

In a condition responsive sensing system having a plurality of condition sense bridge elements, the method comprising the steps of

• providing a bias for each sense element,
• providing an electronic circuit having multiplexers, a signal conditioning circuit path having signal conditioning components, an analog to digital converter, logic control, nonvolatile memory and a digital port for transmitting and receiving data,
• forming the electronic circuit as an ASIC,
• obtaining electronic calibration data for each sense element during manufacture of the system and storing that information in nonvolatile memory,
• connecting the electronic controller to an external controller,
• transmitting data from nonvolatile memory to enable the external controller to perform mathematical corrections to a conditioned digital signal,
• selecting an address of the multiplexers for connecting outputs of a selected bridge sense element to the signal conditioning circuit path and to transmit basic offset and gain calibration data to send conditioning components in the signal conditioning path,
• partially conditioning the addressed sense element using the basic offset and gain calibration data transmitted from nonvolatile memory, to provide a partially conditioned signal,
• converting the partially conditioned signal from an analog format to a digital format in the analog to digital converter to provide a digital signal,
• transmitting the digital signal to the external controller and
• completing the conditioning of the partially conditioned signal by performing mathematical corrections to the digital signal in the external controller using the data transferred from the nonvolatile memory.

In a condition responsive sensing system having a plurality of condition sense bridge elements, the method comprising the steps of

• providing a bias for each sense element,
• forming a sense element diagnostic circuit path the electronic circuit including a summing circuit for summing the plus and minus outputs of the selected sense element and offset and gain components corresponding to the offset and gain correction networks of the signal conditioning circuit path to provide reference data for diagnostic use of sense element and sense element connection faults,
• providing an electronic circuit having multiplexers, a signal conditioning circuit path having signal conditioning components, an analog to digital converter, logic control, nonvolatile memory and a digital port for transmitting and receiving data,
• obtaining electronic calibration data for each sense element during manufacture of the system and storing that information in nonvolatile memory,
• connecting the electronic to an external controller,
• transmitting data form nonvolatile memory to enable the external controller to perform mathematical corrections to a conditioned digital signal,
• selecting an address of the multiplexers for connecting outputs of a selected bridge sense element to the signal conditioning circuit paths and to transmit basic offset and gain calibration data to the signal conditioning components in the signal conditioning path,
• partially conditioning the addressed sense element using the basic offset and gain calibration data transmitted from nonvolatile memory, to provide a partially conditioned signal,
• converting the partially conditioned signal from an analog format to a digital format in the analog to digital converter to provide a digital signal,
• transmitting the digital signal to the external controller and
• completing the conditioning of the partially conditioned signal by performing mathematical corrections to the digital signal in the external controller using the data transferred from the nonvolatile memory.